The supplier said that 5.03 million of this total are electricity customers, 2.87 million are gas customers and 105,000 are telecoms customers.
Scottish & Southern was the subject of speculation that Russian gas giant Gazprom was preparing a takeover bid for it - but last week Gazcom marketing and trading spokesman Phillip Dewhurst moved to calm fears.
"We do not have Centrica or Scottish & Southern in our sights at the moment," he said.
"Our plan in the UK is to grow our retail business organically."
Senior officials at Gazprom say that they are looking to increase the company's presence in the UK market, however.
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